STANDARD BACK UP RING: 

Standard back-up rings are used in both static and dynamic sealing. Made of materials that are resistant to pressure induced flow, the back-up ring keeps a seal from extruding into the clearance gap between mating parts.

Our back-up rings are equivalent to AN6224, AN6246, MS28774, MS28782, and MS28783 specifications.  The PTFE back-up rings are specifically cut to MS28774 specifications.  Both types of back-up rings share a common rectangular cross-section. 

CONTOURED BACK-UP RING: 

Contoured back-up rings are anti-extrusion devices used in both static and dynamic sealing environments. They’re also useful when mating part clearances are not tightly controlled. In either case, they can extend the useful life of O-Rings. Contoured back-up rings have a slightly concave face on one side, providing uniform contact with the entire diameter of the O-Rings they are used with. Sizes correspond with AS568 O-Rings. Whenever possible, the use of two back-up rings is recommended, even in single-acting applications. 

 Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetra-fluoroethylene that has numerous applications. It is also known by the common trade name Teflon. PTFE can be modified for use as a gasketing material with strong chemical resistance properties. It can also be machined or molded into most any shape.